1. Field of the Invention
This invention relates to industrial power transmission apparatus. More particularly, this invention is a new bushing and hub structure which is mountable upon a shaft and can easily be removed from the shaft.
2. Description of the Prior Art
A currently manufactured bushing and hub is described in U.S. Pat. No. 2,269,821 dated Jan. 13, 1942 issued to W. W. Kemphert et al. and entitled "SHEAVE." The bushing described in Kemphert et al. includes a bushing with an integral flange. The bushing is tapered on the outside diameter and contains a concentric, cylindrical bore. The integral flange is located at the largest outside diameter of the taper. The flange contains a number of cap screw holes which are used to pull the bushing into a mating hub. The entire bushing is sawed through or split on one side so the bushing will close in on a shaft and clamp to it as the bushing is pulled into the mating taper of the hub.
Newer drive systems using more compact components than previously used often do not afford enough space for the use of a flanged type bushing such as shown in the Kemphert et al. U.S. Pat. No. 2,269,821. These same drives transmit relatively high torques. Therefore, any more compact hub and bushing than the bushing and hub described in the Kemphert et al. patent must not only be compact enough to fit into the newer drive systems of today, but must also be capable of transmitting relatively high torques.
A bushing and hub arrangement which is more compact than the bushing and hub arrangement of Kemphert et al. is described in U.S. Pat. No. 2,402,743 dated Jun. 25, 1946 issued to Firth and entitled "MOUNTING FOR SHEAVES, ETC." Since the Firth structure has no flange, the bushing is pulled into place using several set screws and threaded holes which are located half in the bushing and half in the hub. However, even though the set screw itself acts as a shear bearing member between the bushing and the hub, the forces pulling the bushing into the mating hub and the clamping forces on the shaft are very limited. The forces are limited because neither the threads in the bushing nor the threads in the hub have a full circumference of threads around the set screws.
For newer drive systems a split tapered bushing system which is more compact than the currently manufactured Kemphert et al. hub and bushing but still has the same force magnitude as the Kemphert et al. type hub and bushing to withstand the relatively high torques transmitted by the newer drive systems would obviously be highly desirable.
My invention is a new split tapered bushing system for use in power transmission systems which is more compact than the currently manufactured flanged bushings of the type shown in the Kemphert et al patent and yet provides sufficient clamping ability to be used with the newer drive systems which transmit relatively high torques.